Posties in England have for years used s delivery bike made by Pashley. It looks great and to me looks sturdy enough to last for years. It's called the Mailstar. Recently, the Royal Mail made a decision to phase them out. I read about it in the Guardian.
Like many activities that involve actually getting out of bed in the morning, it is apparently an "occupational health and safety issue". Instead, posties will from now on add to Britain's already congested roads by driving a van. Apparently that is safer than riding a bike at walking speed on a pavement.
Thankfully, Australia is still a sensible country. I was walking through North Adelaide this morning. The postie up ahead was not on one of the Honda mopeds they usually use but a bicycle with a big crate on the front. I don't know if this is new or they have been using them for years. Whatever. Go Australia Post!